Device for cutting inchained thread loops between stitched articles



N0v..1o, 1931.- F. LUTZ. 1,831;5o1

DEVICE FOR CUTTING INCHAINED THREAD LOOFS BETWEEN STITCHED ARTICLES Filed NOV. lO, 1928 2 Sheets-51166K l Nov. 1o, 1931. v F U'Tz 1 1,831,501

DEVICE FOR CUTTING INCHAINED THREAD LQOPS BETWEEN STI TCHED ARTICLES Filed Nov. 10, 1928 2 sheets-sheet 2 Patented Nov. 10, 1931 vUNITED STATES PATENT OFFICE MASCHINENFABRIK G. M. B. H., OF STUTTGART, GERMANY DEVICE FOR CUTTING- INCHAINED THREAD LOOPS BETWEEN STITCEED ARTICLES Application led November 10, 1928, Seria! No. 318,546, and in Germany March 13, 1928.

The invention relates to new and useful'improvements in a device for cuttinor the inchained thread loops between stitched articles, and` more particularly to a chain` cutting device which is operating continuously during the operation of the machine to which it is attached.

An object of the invention is to provide a chain cutting device of the above character wherein the cutting devices which sever the chain are movable back and forth in unison with .the feed ofthe machine.

A further object of the invention is to provide a cutting device for severing the .inchained thread loops between stitched articles wherein the inchained thread loops may be automatically severed close to the edge of the stitched article passing from the machine.

A further object of the invention is to provide a machine, having continuously operating devices positioned so that the fabric being stitched will pass freely over the same, with means for depressing the inchained' thread loops into the path of the cutting devices as said inchained thread loops are fed away from the' stitching point and so long as there is no article passing beneath the presser foot.

` These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of the invention Fig. 1 is a view partly in section and partly in end elevation showing a machine having the improvements embodied therein.

Fig. 2 is a view partly in section and partly from the front of the parts shown in Fig. l.

Fig. 3 is an enlarged sectional view showing the severing devices, the auxiliary chain depressing foot, a portion of the supporting throat plate and the feeding section which feeds the inchained thread loops.

Fig. 4 is a transverse sectional view through the throat plate and a portion of the presser foot in the region of the cutting devices when said cutting devices are at the forward end of their back and forth movement.

The invention is directed to cutting devices for severing the inchained thread loops between stitched articles. These severing devices are mounted so as to move back and forth bodily in the line ofl feed, while the severing devices have a movement relative to each other for severing the inchained thread loops in a plane at right angles to' the line of feed. As embodied in the drawings, the severing devices are mounted on the feed bar and have a bodily movement up and down with the feed bar and back and forth with the feed @o bar. One of these severing devices is stationary relative to the feed bar, while the other is mounted on the feed bar so as to have a rock# ing movement ywhereby it will cooperate with the stationary cutting device in the, severing 65' of the inchained thread loops. The throat plate is provided with a suitable opening in which these severing devices operate. It is also provided with supporting bridge members with which an auxiliary presser foot cooperates. The feed dog is provided with a section cooperating with this auxiliary foot "for feeding theinchained thread loops.

The machine is provided with the usual presser foot sections and the feed dog has main feeding sections cooperating therewith. These main feeding sections are on a higher level than the auxiliary sections and the cutting devices are so disposed that the extreme upper points of the cutting devices are slightly below a plane containing the upper faces of the main sections of the feed dog. They are, however, slightly above a plane containing the upper faces of the auxiliary section of the feed dog which feeds the inchained 35 thread loops. The severing devices are located at the rear of the presser foot and are raised so as to sever the inchained thread loopswhen there is no article beneath the presser foot, at a point well underneath the presser foot and comparatively close to the needle. As' a result as soon as the' article passes from beneath the presser foot the 1nchained thread loops will be s evered very close to the stitched article.

- Referring more in detail to the drawings, the machine embodying the invention consists of a work supporting frame 1 in which is mounted a main operating shaft 2 provided with two eccentric's 3 and 4 which are utilized 100 for actuating the feeding mechanism. The feeding mechanism includes a main feed bar 5 carrying a main feed dog 6. The eccentric 3 cooperates with an eccentric strap pivoted to the feed bar for raising and lowering the same. The eccentric 4 cooperates with an eccentric strap 7 which is pivoted to the feed rocker 9. The feed rocker 9 is mounted for oscillation on a pivot rod 8. The feed bar 5 is pivoted to the feed rocker at 10. The inchained thread loops are severed by cutting devices which include two cooperating cutting blades 1 and 12. The blade 11 is fixed to the feed bar by means of a screw 13. The blade 12 is a movable blade and this blade 12 is secured to an arm 15 by means of a clamping screw 14. The arm 15 is secured to a hub which is secured to a shaft 16 journaled at 17 in suitable lugs carried by the feed bar 5. The two cutting devices 11 and 12 are, therefore, moved bodily back and forth with the feed bar and also'bodily up and down with the feed bar. The shaft 16 carrying the arm 15 is oscillated by means of a link 18. The feed rocker 9 is provided with an arm 19. Mounted on this arm 19 is a ball stud 20. The link 18 is connected to this ball stud. The ball stud is shiftable in a slot in the end of the arm 19 and is secured in adjusted positions by means of a clamping screw 20a.

As the feed rocker is moved back and forth the arm 19 will be raised and lowered. The upward movement of the arm 19 through the link 18 will rock theshaft 16 and cause the movable cutting blade 12 to partake of a shearing movement relative to the stationary cutting blade 11. A spring 16a surrounding the shaft 16 and bearing against 4the hub carrying the arm 15 normally presses the movable blade into yielding engagement with the stationary blade, thus insuring a perfect shearing cut.

The incha-ined thread loops have been indicated in the drawings at 22. These inchained thread loops are formed by the stitching mechanism between stitched articles. The machine is particularly adapted for closing filled bags and in stitching articles of this kind it is often customary to provide a cord or strip either of fabric or other suitable reinforcing material in which the stitches are embedded during the closing of the bag. This cord or strip is continuous and will extend from one stitched article to the next stitched article. The severing devices will sever this cord or strip as well as the inchained thread loops, and, therefore` lin the description and claims it will be understood that reference to the inchained thread loops is not intendedas a limitation but as a general reference to the connecting portions between stitched articles whether they be merely thread loops or include as well a reinforeing strip or cord in' which the thread loops are embedded between the stitched articles.

The material being stitched is held against the lthroat plate 33 on the supporting frame 1 by means of apresser foot consisting, as illustrated, of two sections 29 and 30. These presser feet are carried by presser bars 34. The needle of the machine is indicated at 35. The presser foot section 30 is provided with a slot or recess extending longitudinally thereof directly in the line of feed and an auxiliary presser foot member 23 is located in this slotor recess. Directly beneath this auxiliary section 23 are bridging portions 25 and 26 carried by the throat plate 33. The feed dog is provided with a feeding section 31 which moves back and forth and up and down in aslot between these bridging portions 25 and 26. The section 31 of the feed dog is on a much lower level than the main feeding sections of the feed dog 6. The auxiliary section 23 is recessed at the rear end thereof as indicated at 28 and the extreme upper points 27, 27 of the cutting blades eX- tend up into the recess during the cutting of the inchained thread loops.

When an article to be stitched is passing beneath the presser foot the auxiliary section which is yieldingly depressed by a spring 24 will be held raised so that its lower face is substantially flush with the lower faces of the sections 29 and 30 of the presser foot. The cutting blades are so positioned on the feed bar that the points 27, 27 are lower than the upper faces of the mainsections of the feed dog, and, therefore, the article being stitched will be raised by the feed dog during the feeding of the articles so that the article is entirely above the points and the points will not cut into the article or the inchained thread loops embedded therein. When the article passes from beneath the foot then the presser foot will be lowered onto thethroat plate or the main feeding sections and the auxiliary portion 23 of the presser foot will move down to a lower level bearing on the inchained thread loops and pressing the same against the bridging portions 25 and 26 or the feeding section 31. The upper face of the feeding section 31 is located beneath the level of the points 27, 27 of the chain cutter, and, therefore, the inchained thread loops resting on this feeding section 31 will be placedin the path of the chain cutting devices. The chain cutting devices move with the feed dog and will sever the inchained thread loops during the feeding of the inchained thread loops and as the feed dog is lowered from engagement with the inchained thread loops and moves toward the front of the machine so asto obtain a new hold on the forming inchained thread loops the cutter will again rise with the feed dog and sever the inchainedt-hread loops. 'Just so longv as the machine is chaining between stitched articles the severing devices will sever the inchained thread loops at each o eration.`

Vhen the stitched article is eneath the presser foot then the severing devices are ineffective to cut the inchained thread loops even though they may extend directly above the severing devices. As soon, however, as the stitched article passes from beneath the presserfoot so that the auxiliary section 23 1s free to move beneath the plane of the lower face of the presser foot sections 29 and 30 then the inchained thread loops will be depressed into the range of the severing devices and severed. The severing devices move back and forth in a slot in the throat plate 'and have a range of movement from a position close to the bridging portion 25 of the throat plate, as shown in Fig. 3, to a position well out from beneath the presser foot as shown in Fig. 1. The inchained thread loops will, therefore, be cut very close to the -material of the article being stitched for the-reason that just as soon as the auxiliary foot 23 slides down off from the edge of the 25 passing stitched article the chain will be severed. While another article is being placed in the machine the chain loo s are being' formed but they are being cut by the severing devices so that when the article reaches the needle the length of inchained thread loops which will be attached to the article is comparatively short as it extends merely from the position of the cutting devices to the path of the needle where the inchained thread loops are formed. As soon as the article raises 4the presser foot the severing of the inchained thread loops ceases and a. proper length of inchained thread loops will be' formed prior to the beginning of the stitch- 40 ing.

It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the inventionas set forth in the appended claims.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent, is

l. In a sewing machine the combination of a feeding mechanism including afeed dog, a presser foot cooperating with saidffeed dog, chain severing devices operating in a plane at right angles to the feed for severing the inchained thread loops between stitched articles, means for continuously actuating said severing devices, andmeans whereby said severing devices are moved bodily in unison with the feed dog during the severing of the inchained thread loops.

2. In a sewing machine the combination of a feeding mechanism including a feed dog,

a presser foot cooperating with said feed dog, chain severing devices for severing the inchained thread loops between stitched articles, means for continuouslyactuating said severing devices, means associated with the presser foot for directing the inchained thread loops into the severing devices, and means whereby said severing devlces are moved bodily in unison with the feed do in a plane at right angles to the feed for severing the inchained thread loops between A stitched articles, means for continuously actuating said chain severing devices, means forA automatically directing the inchained thread loops between stitched articles into the severing devicesimmediately upon the stitchedy article passing from beneath the presser foot, and means for moving said severing devices bodily inunison with the feed dog during the severing of the inchained thread loops.

4. In a sewing machine the combination of a feeding mechanism including a feed bar, a feed dog carried thereby, a presser foot cooperating with the feed dog, chain severing devices mounted on the feed bar and movable bodily back and forth and up and down therewith, means for actuating said severing devices continuously .during the operation of the feeding mechanism, said chain severing 'devices being disposed in rear of the feed' dog and bodily movable beneath the rear end of the presser foot, and means for directing the inchained thread loops into the severing devices when thestitched article passes from beneath the presser foot.

5. In a sewing machine thecombination of a feeding mechanism including a feed bar, a feed dog carried thereby, a presser foot cooperating with the feed dog, chain severing devices carried by the feed bar having their` upper cutting portions disposed beneath a plane containing the main feeding sections of the feed dog, said feed dog having auxiliary feeding sections located in a'plane below the extreme upper cutting portionsof the severing devices, said presser foot having yielding means for depressing the inchained thread loops into range of the severing devices when a stitched article passes from beneath the foot.

6. In a sewing machine the combination of a feeding mechanism including a feed bar, a feed dog carried thereby, said feed dog having main'and auxiliary feeding sections arranged indifferent levels, a chain severing device having the extreme upper cutting portions disposed at a level beneath the level of the main feeding sections and above the level ofthe auxiliary feeding sections, means continuously actuating said severing devices, .a presser foot having an auxiliary 'yielding section adapted Ato cooperate with .er foot having main sections coo said auxiliary feeding section for feeding the inchained thread loops and for directing the inchained thread loops into the severing devices when a stitched article passes from beneath the presser foot.

7. In a sewing machine the combination of a feeding mechanism including a feed bar, a feed dog carried thereby, said feed dog having mainand auxiliary feeding sections arranged in different levels, a chain severing device having the extreme upper cutting portions disposed at a level beneath the level ofthe main feeding sections and above the level of the. auxiliary feeding sections, means continuously actuating said severing devices, a presser foot having an auxiliary yielding section adapted to cooperate with said auxiliary feeding section for feeding the inchained thread loops and for directing the inchained thread loops into the severing devices when a stitchedL article passes from beneath the presser foot, and means whereby said severing devices are moved bodily in unison with the feed dog during the severing of the inchained thread loops.

8. In a sewing machine the combination of a throat plate having a feed slot centrally thereof and a bridging portion at each end of the slot disposed on a lower level than the upper worksupporting face of the throat plate, a feed dog having main feeding sections disposed on a level so as to operate in feeding an article placed on the main supporting surfaces of the throat plate and having an auxiliary feeding section for feeding incliained thread loops resting on the bridging portions of the throat plate, a presser foot having main sections cooperating with the main sections of the feed dog, and a yielding auxiliary section cooperating with the auxiliary section of the feed dog, severing devices located at the rear of the presser foot for severing inchained thread loops, the extreme upper cutting portions of the severing devices being disposed on a level lower than the level of the main sections of the feed dog and above the level of the auxiliary section of the feed dog, and means for continuously actuating said severing devices.,

9. In a sewing machine the combination of a throat plate having a feed slot centrally thereof and a bridging portion at each end of the slot disposed on a lower level than the upper work supporting face of the throat plate, a feed dog having main feeding sections disposed on a level so as to operate in feeding an article placed on the main supporting surfaces of the throat plate and having an auxiliary feeding section for feeding inchained thread loops resting on the bridging portions of the throat plate, a pressratin with the main sections of the feed og, an

a yielding auxiliary section cooperating with the auxiliar section of the feed dog, severing devices ocated at the rear of the presser foot for severing inchained thread loops, the extreme upper cutting portions of the severing devices being disposed on alevel lower than the level of the main sections of the feed dog and above the level of the auxiliary section of the feed dog, means for continuously actuating said severing devices, and

`means whereby said severing devices are moved bodily in unison with the feed do during the severing of the inchained thre loops.

10. In a sewing machine the combination of a feeding mechanism including a presser foot, a feed dog, means for raising and lowering and for moving said feed dog back and forth, a chain sever1ng device mounted on the feed bar carrying said feed dog and movable up and down and back and forth with said feed dog, said chain severing device having continuously moving severing members, said feed dog having a main fabric feeding section disposed on a level abovg the cutting portions of said severing devices, andan auxiliary chain feeding section disposed on a level beneath the level of the cutting portions of the chain severing devices, and means for directing the inchained thread loops into the severing devices when the artil 

